Display Possible cause/Suggested solution
L1 Phase Loss
L2 Phase Loss
L3 Phase Loss
During prestart checks the starter has detected a phase loss as indicated.
In run state, the starter has detected that the current on the affected phase has dropped below 3.3% of
the programmed motor FLC for more than 1 second, indicating that either the incoming phase or connec-
tion to the motor has been lost.
Check the supply and the input and output connections at the starter and at the motor end.
Phase loss can also be caused by a failed SCR, particularly an SCR that has failed open circuit. A failed SCR
can only be definitely diagnosed by replacing the SCR and checking the starter's performance.
Related Pars.: None
L1-T1 Shorted
L2-T2 Shorted
L3-T3 Shorted
During prestart checks the starter has detected a shorted SCR or a short within the bypass contactor as
indicated.
Related Pars.: none
Motor Overload The motor has reached its maximum thermal capacity. Overload can be caused by:
- The soft starter protection settings not matching the motor thermal capacity.
- Excessive starts per hour
- Excessive throughput
- Damage to the motor windings.
Resolve the cause of the overload and allow the motor to cool.
Related Pars.: 1-1, 1-2, 1-3, 1-4, 16-1
Motor Connection The motor is not connected correctly to the soft starter for inline or inside delta use.
- Check individual motor connections to the soft starter for power circuit continuity.
- Check connections at the motor terminal box.
Related Pars.: 15-7
Motor Thermistor The motor thermistor input has been enabled and:
-
The resistance at the thermistor input has exceeded 3.6 kΩ for more than one second.
- The motor winding has overheated. Identify the cause of the overheating and allow the motor to cool
before restarting.
- The motor thermistor input has been open.
Note: If a valid motor thermistor is no longer used, a 1.2 kΩ resistor must be fitted across terminals 05,
06.
Related Pars.: 16-9
Network Comms The network master has sent a trip command to the starter, or there may be a network communication
problem.
Check the network for causes of communication inactivity.
Related Pars.: 16-11
Parameter out of Range - A parameter value is outside the valid range.
The LCP will indicate the first parameter which is out of range. Press RESET to go to the parameter and
adjust the setting.
Related Pars.: None
Phase Sequence The phase sequence on the soft starter's input terminals (L1, L2, L3) is not valid.
Check the phase sequence on L1, L2, L3 and ensure the setting in Par. 2-1 is suitable for the installation.
Related Pars.: 2-1
2 Troubleshooting MCD 500 Service Manual
8
MG.17.L1.02 - VLT
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is a registered Danfoss trademark
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